Reverse Engineer a Tape Measure Hook

Engineering Context

A maintenance department needs a replacement tape hook, but the supplier no longer provides the part file.

What You Will Practice

• Use calipers to collect part dimensions
• Create fully constrained sketches
• Build a parametric model
• Compare CAD geometry to a physical part

What You Need

• Tape measure hook or similar flat metal part
• Calipers
• Fusion 360
• Engineering notebook
• Optional flatbed photo with scale

Instructions

1. Identify the part’s datums and create a measurement plan.
2. Measure overall length, width, thickness, holes, slots, bends, and feature spacing.
3. Create a parameter table before sketching.
4. Build the base profile with geometric and dimensional constraints.
5. Add holes, slots, fillets, and bends or approximations in a logical feature order.
6. Verify that every sketch is fully constrained.
7. Create a technical drawing with the dimensions needed for inspection.
8. Compare at least five CAD measurements with the physical part and calculate error.

Engineering Requirements

• Fully constrained sketches
• All critical dimensions driven by parameters
• Five comparison measurements within +/-0.5 mm
• Realistic fillets and feature order
• Complete drawing and STL export

Constraints & Safety

• Do not disassemble a tape measure spring mechanism
• Model only the approved hook component
• Use metric units
• Complete within two class periods

What You Submit

• Measurement plan and table
• Fusion 360 file
• Parameter list
• Technical drawing PDF
• STL file
• CAD-to-part error table

Reflection Questions

1. Which measurement controlled the most geometry?
2. Where was the largest error?
3. How did constraints make revision easier?
4. What manufacturing process likely created the original part?